Aqueous coating composition

ABSTRACT

An aqueous coating composition including a polyurethane polymer which contains carboxylic acid groups, a crosslinking agent, a wetting agent, a slip aid, and a UV stabilizing agent is provided. Coatings prepared from the aqueous coating composition are durable and have low surface friction, flexibility at low temperatures, and adhesion to low surface energy substrates. A method of preparing a substrate coated with the aqueous coating composition and an article containing the coated substrate are also provided. The aqueous coating composition is useful for providing a protective coating with a low friction surface for automotive weatherstrip.

This invention relates to an aqueous coating composition suitable forproviding a coating which has a low friction surface. Further, thisinvention relates to an aqueous coating composition suitable forproviding a coating with improved adhesion to low energy surfaces suchas untreated ethylene-propylene-diene (EPDM) rubber. More particularly,this invention relates to an aqueous coating composition including apolyurethane polymer, a crosslinking agent, a slip aid, a wetting aid,and a UV inhibitor. Also, this invention relates to a method of applyingthe aqueous coating composition onto a substrate. Further, thisinvention relates to an article prepared containing a coating formedfrom the aqueous coating composition. The aqueous coating composition isuseful for providing a protective coating with a low friction surfacefor automotive weatherstrip.

The present invention provides a coating that has a low frictionsurface. As used herein, a low friction surface refers to surfaceshaving a low coefficient of friction. Coatings with low frictionsurfaces are desirable is many applications including, for example,coatings for weatherstrip used in automobiles. Weatherstrip inautomobiles may be used to provide a seal between two components in thebody of an automobile. For example, the weatherstrip used to provide aseal between window glass and a door frame typically has a coating witha low friction surface to allow lowering or raising of the window glasswith minimum resistance. The coating on the weatherstrip also providesresistance to degradation by abrasion from movement of the window glass.Further, the coating on the weatherstrip must also remain flexible overa wide range of temperatures in order to provide a seal at temperaturesof −40° C.

U.S. Pat. No. 5,115,007 discloses a coating composition useful forpreparing abrasion-resistant, low friction coatings on EPDM rubber. Thedisclosed coating composition includes a blocked polyurethane prepolymercontaining blocked isocyanates groups, a crosslinking agent coreactivewith the blocked isocyanate groups, a compatible silicone oil, and anon-reactive solvent such as toluene. The coating composition is appliedto a substrate and then cured to form a coating containing apolyurethane polymer. The coating composition may be applied onto EPDMrubber without prior application of a primer or surface treatment of theEPDM rubber. However, this reference does not disclose an aqueouscomposition containing a polyurethane polymer.

The use of coating compositions containing organic solvents can resultin the release of the organic solvent to the atmosphere and workerexposure to the organic solvent. Aqueous based coating compositions aredesired for preparing abrasion-resistant, low friction coatings suitableas coatings for weatherstrip and, further, which may be applied tountreated EPDM rubber.

I have found an aqueous coating composition which provides aabrasion-resistant coating with low surface friction and is suitable forapplication onto EPDM rubber. Further, this aqueous coating compositionmay be applied onto untreated EPDM rubber to provide a coating with goodadhesion to the untreated EPDM rubber.

In the first aspect of this invention, an aqueous coating composition isprovided which includes, based on the weight of the aqueous coatingcomposition: from 10 to 70 weight % of at least one polyurethanepolymer, wherein the polyurethane polymer contains at least twocarboxylic acid groups; from 1 to 60 weight % of at least onecrosslinking agent; from 0.01 to 4 weight % of at least one wettingagent; from 0.1 to 15 weight % of at least one slip aid; and from 0.01to 20 weight % UV stabilizing agent.

In the second aspect of this invention, a method of preparing a coatedsubstrate is provided including the steps of preparing an aqueouscoating composition containing: from 10 to 70 weight % of at least onepolyurethane polymer, wherein the polyurethane polymer contains at leasttwo carboxylic acid groups; from 1 to 60 weight % of at least onecrosslinking agent; from 0.01 to 4 weight % of at least one wettingagent; from 0.1 to 15 weight % of at least one slip aid; and from 0.01to 20 weight % UV stabilizing agent; applying the aqueous coatingcomposition to a substrate; drying or allowing to dry the aqueouscoating composition to provide a precrosslinked coated substrate; andcuring or allowing to cure the precrosslinked coated substrate toprovide the coated substrate.

In the third aspect of this invention, an article including a coatedsubstrate containing a substrate and a coating prepared from an aqueouscoating composition containing from 10 to 70 weight % of at least onepolyurethane polymer, wherein the polyurethane polymer contains at leasttwo carboxylic acid groups; from 1 to 60 weight % of at least onecrosslinking agent; from 0.01 to 4 weight % of at least one wettingagent; from 0.1 to 15 weight % of at least one slip aid; and from 0.01to 20 weight % UV stabilizing agent.

The aqueous coating composition of this invention contains apolyurethane polymer, a crosslinking agent, a wetting agent, a slip aid,and a UV stabilizing agent. The aqueous coating composition may beapplied onto untreated EPDM rubber and provides a durable low frictioncoating.

The polyurethane polymer contained in the aqueous coating composition ofthe present invention includes aliphatic polyurethane polymers andaromatic polyurethane polymers. The polyurethane polymer containscarboxylic acid groups to provide reactive moieties suitable forreaction with the functional groups of the crosslinking agent. Thepolyurethane polymer must contain a minimum level of carboxylic acidgroups to provide sufficient crosslinking in order to obtain coatingswith adequate durability. An excessive level of carboxylic acid groupsin the polyurethane polymer may adversely affect the moisture resistanceof the coating prepared from the coating composition containing thepolyurethane polymer. Polyurethane polymers suitable for the presentcoating composition may contain levels of carboxylic acid characterizedby an acid number in the range of 5 to 50, preferably in the range of 10to 40, and more preferably in the range of 20 to 40. Further, thepolyurethane polymer may have a weight average molecular weight, Mw, inthe range of 20,000 to above 2,000,000, preferably in the range of50,000 to above 2,000,000, and more preferably in the range of 100,000to above 2,000,000. The polyurethane polymer may be in the form of anaqueous dispersion containing polyurethane polymer particles with anaverage diameter in the range of 20 nm to 1,000 nm, preferably in therange of 30 nm to 500 nm, and more preferably in the range of 40 nm to300 nm. The aqueous medium containing the polyurethane polymer particlesmay also contain water miscible organic solvents such as1-methyl-2-pyrrolidone and methyl ethyl ketone. Preferably, the aqueousdispersion containing the polyurethane polymer does not contain anorganic solvent. The aqueous coating composition may contain from 10 to70 weight %, preferably from 20 to 60 weight %, and more preferably,from 30 to 50 weight % polyurethane polymer, based on the weight of theaqueous coating composition.

The aqueous coating composition of the present invention also contains acrosslinking agent. The crosslinking agent is a polymer or a nonpolymercontaining at least two functional groups capable of reacting with thecarboxylic acid groups of the polyurethane polymer. Suitable functionalgroups include epoxides, oxazolines, melamines, carbodiimides, andisocyanates stable in water such as blocked isocyanates. Preferredfunctional groups are oxazolines and melamines. More preferred areoxazolines as the functional groups. The backbones for polymers withpendant functional groups suitable as the crosslinking agent includeacrylates, methacrylates, styrene butadienes, styrene acrylates, andvinyl chlorides. Nonpolymers containing at least two function groupsinclude, for example, phenyl glycidyl ether, melamine monomers, anddiepoxide compounds. The crosslinking agent may be a neat solid orliquid, or alternatively may be solubilized or dispersion in an organicsolvent or aqueous medium. Preferred crosslinking agents are neat solidsor liquids which are soluble or dispersed in water. Other preferredcrosslinking agents are aqueous dispersions of polymers with containoxazoline, epoxide, or blocked isocyanate groups. In one embodiment, thecrosslinking agent is an aqueous dispersion of a styrene-acryliccopolymer which contains oxazoline groups. The aqueous coatingcomposition of the present invention contains from 1 to 60 weight %,preferably from 3 to 45 weight %, and more preferably, from 5 to 35weight % crosslinking agent, based on the weight of the aqueous coatingcomposition.

In the aqueous coating composition of the present invention, the ratioof the number of carboxylic acid groups contained in the polyurethanepolymer to the number of functional groups contained in the crosslinkingagent may be in the range of 10:1 to 1:10, preferably in the range of5:1 to 1:5, and more preferably in the range of 3:1 to 1:3.

Another component of the aqueous coating composition is a wetting agent.The wetting agent lowers the surface tension of the aqueous coatingcomposition to increase the ability of the aqueous coating compositionto wet the surface of a substrate during application, in particular,substrates with low energy surfaces. As used herein, a wetting agentdecreases the surface tension of water by greater than 1 dyne/cm for a0.01 weight % solution of the wetting agent in water. Suitable wettingagents include silicone surface additives such as polysiloxanesincluding polyether modified poly-dimethyl-polysiloxane, polyestermodified poly-dimethyl-siloxane; fluorosurfactants such as Zonyl™fluorosurfactants (Zonyl is a trademark of E. I. du Pont de Nemours andCo.); surfactants based on acetylenic alcohol, diol, and glycolchemistry such as Surfynol™ 61 surfactant and Dynolm 604 surfactant(Surfynol and Dynol are trademarks of Air Products and Chemicals, Inc.)and mixtures thereof. The aqueous coating composition may contain from0.01 to 4 weight % of the wetting agent, preferably from 0.1 to 4 weight%, more preferably from 0.5 to 4 weight %, based on the weight of theaqueous coating composition.

The aqueous coating composition of this invention also contains 0.1 to15 weight % of at least one slip aid, based on the weight of the aqueouscoating composition. The slip aid may be dispersible or soluble in thewater phase of the aqueous coating composition. The slip aid assists inlowering the friction of the surface of the coating prepared from theaqueous composition. As used herein, a surface with low friction has adynamic coefficient of friction with a value of 3 or lower against glassas measured by ASTM D 1894. The aqueous coating composition preferablyprovides a coating with a low friction surface. Preferably, the surfaceof the coating prepared from the aqueous coating composition has acoefficient of friction with a value of 1.5 or lower, more preferably, acoefficient of friction with a value of 1.1 or lower.

Various slip aids are suitable for use in the aqueous coatingcomposition including waxes, silicone additives, fluorinated additives,and mixtures thereof. Suitable waxes include polyethylene waxes,polypropylene waxes, and paraffin waxes. In one embodiment, the aqueouscoating composition contains an oxidized polyolefin wax, such asprepared by the process disclosed in U.S. Pat. No. 6,169,148. Suitablesilicone additives include polysiloxanes, modified polysiloxanes such aspolyether modified poly-dimethyl-polysiloxanes, polyester modifiedpoly-dimethyl-polysiloxanes; hydroxy functional silicones. Suitablefluorinated additives include polytetrafluoroethylene waxes or blendscontaining polytetrafluoroethylene waxes such as Fluo HT (Micro Powders,Inc.), Aqua Polysilk 19 wax (Micro Powders, Inc.), and Microspersion HT(Micro Powders, Inc.). The waxes, silicone additives, and fluorinatedadditives may be provided as solutions, dispersions, or emulsions suchas anionic wax emulsion, anionic paraffin/polyethylene emulsions or aspowders such as polyethylene powder and modified synthetic wax powder.Combinations or mixtures of waxes, silicone additives, and fluorinatedadditives may be used in order to provide a coating with a low frictionsurface and other desired properties.

The exterior use of the coating prepared from the aqueous coatingcomposition results in exposure to ultraviolet light (UV), specificallylight with a wavelength of less than 380 nm, which may decrease thedurability of the coating. To protect the coating prepared from thecoating of this invention from inimical UV light, the aqueous coatingcomposition also contains an ultraviolet stabilizing agent, referred toherein as an “UV stabilizing agent”. The UV stabilizing agent is amaterial which is capable of reducing or eliminating the deleteriouseffects of the of UV light on the coating. The UV stabilizing agent mayabsorb, scatter, or reflect the UV light. The UV stabilizing agent maybe a UV absorbing molecule such as a hindered amine, a substitutedhydroxyphenyl benzotriazole, benzotriazole, benzophenone, a substitutedacrylonitrile, or a phenol-nickel complex; or a pigment such as carbonblack or titanium dioxide. Other suitable pigments include solid beadand microsphere pigments containing voids and vesicles. Examples ofsolid bead pigments include polystyrene and polyvinyl chloride beads.Examples of microsphere pigments, which include polymer particlescontaining one or more voids and vesiculated polymer particles aredisclosed in U.S. Pat. No. 4,427,835; U.S. Pat. No. 4,920,160; U.S. Pat.No. 4,594,363; U.S. Pat. No. 4,469,825; U.S. Pat. No. 4,468,498; U.S.Pat. No. 4,880,842; U.S. Pat. No. 4,985,064; U.S. Pat. No. 5,157,084;U.S. Pat. No. 5,041,464; U.S. Pat. No. 5,036,109; U.S. Pat. No.5,409,776; and U.S. Pat. No. 5,510,422. The aqueous coating of thisinvention may contain from 0.01 to 20 weight % UV stabilizing agent,preferably from 0.02 to 15 weight % UV stabilizing agent, and morepreferably, from 0.03 to 10 weight % UV stabilizing agent, based on theweight of the aqueous coating composition.

The aqueous coating composition may optionally contain a pigment. Theaqueous coating composition may contain from 0 to 25 weight % pigment,preferably from 0.5 to 15 weight % pigment, and more preferably from 1to 10 weight % pigment, based on the weight of the aqueous coatingcomposition. Suitable pigments include carbon black; titanium dioxide;iron pigments such as solid iron oxide; antimony oxide pigments; bariumpigments; calcium pigment; zirconium pigments; chromium pigments;magnesium pigments; lead pigments; zinc sulfide; lithopone; phthaloblue; phthalo green; metallic pigments such as aluminum; pearlescentpigments; opalescent pigments; iridescent pigments; and plastic pigmentssuch as solid bead and microsphere pigments containing voids andvesicles.

Optionally, a flatting agent may be added to the aqueous coatingcomposition to provide coatings with low levels of gloss. The aqueouscoating composition may contain from 0 to 20 weight % flatting agent,preferably from 0.5 to 15 weight % flatting agent, and more preferablyfrom 1 to 10 weight % flatting agent, based on the weight of the aqueouscoating composition. Suitable flatting agents include silicas, talcs,ceramics, clays, heavy metal soaps, diatomaceous earth, glass spheres,and mixtures thereof. In one embodiment, the aqueous coating compositioncontains from 2 to 10 weight % silica flatting agent, based on theweight of the aqueous coating composition.

The aqueous coating composition may optionally contain a catalyst toaccelerate the crosslinking reaction between the carboxylic acid groupsof the polyurethane polymer and the functional groups of thecrosslinking agent. The catalyst may be added to the aqueous coatingcomposition during the mixing step to prepare the aqueous coatingcomposition or may be added to the aqueous coating compositionimmediately prior to application to a substrate.

The solids level of the aqueous coating composition is typically in therange 20 to 50 weight % solids, based on the weight of the aqueouscoating composition. Aqueous coating compositions with higher levels ofsolids may be prepared, subject to the availability of components withhigh solids levels and the viscosity required for application. A solidslevel of less than 20 weight % may also be employed but requires theevaporation of larger amounts of water to dry the aqueous coatingcomposition.

The pH of the aqueous coating composition is typically in the range of6.5 to 10, preferably in the range of 7 to 9, and more preferably, inthe range of 8 to 9, to increase the stability of the polyurethanepolymer in the aqueous coating composition and to minimize thecrosslinking reaction between the carboxylic acid groups of thepolyurethane polymer and the crosslinking agent prior to application. Avolatile base may be used to adjust the pH of the aqueous coatingcomposition. Suitable volatile bases include ammonia, lower alkylamines, triethanolamine, 2-dimethylaminoethanol, N-methylmorpholine,ethylenediamine, and morpholine.

The aqueous coating composition may optionally contain conventionalcoating adjuvants such as, for example, biocides, coalescents, fillers,rheology modifiers or thickeners, surfactants, buffers, neutralizers,freeze-thaw additives, wet edge aids, humectants, antifoaming agents,dispersants, and anti-oxidants.

The aqueous coating composition may be prepared by combining the variouscomponents with mixing. The addition order of the components is notimportant. During the step of mixing the various components, the pH ofthe mixture is preferably maintained at or above a value of 6.5. The pHmay be adjusted by the addition of acid or base. Preferably, the pH israised with a volatile base.

Various substrates may be coated with the aqueous coating compositionincluding plastics, elastomers, rubbers, wood, metal, paper, concrete,masonry, concrete, leather, and textiles. The aqueous coatingcomposition is especially suitable for coating elastomeric or rubbersubstrates such as rubbers including acrylonitrile rubber, butyl rubber,chloroprene rubber, chlorosulfonated polyethylene rubber,ethylene-propylene rubber, ethylene-propylene-diene rubber, halobutylrubber, halogenated nitrile rubber, isoprene rubber, natural rubber,neoprene rubber, nitrile rubber, polyacrylic rubber; polyurethaneelastomers; thermoplastic elastomers such as polyamide block copolymers,polyester block copolymers, polystyrene block copolymers, polyurethaneblock copolymers, and polypropylene/ethylene-propylene copolymer blends;thermoplastic polyolefins; polysulfides; propylene oxide polymers;epichlorohydrin polymers; and phosphonitrilic fluoroelastomers.Preferably the substrate is selected from chlorosulfonated polyethylenerubber, ethylene-propylene rubber, ethylene-propylene-diene rubber,halogenated nitrile rubber, thermoplastic elastomers, thermoplasticpolyolefins, propylene oxide polymers, or epichlorohydrin polymers.Ethylene-propylene-diene rubber is an especially preferred substrate.

A substrate with a low energy surface such as EPDM is typicallypretreated with application of a primer coating, exposure to UV light,exposure to a corona discharge, or exposure to plasma to increase thesurface energy. The composition of this invention may be applied ontoeither a substrate with a pretreated surface or a substrate with anuntreated low energy surface. In one embodiment, the aqueous coatingcomposition is applied onto a low energy surface that has not beenpretreated.

Conventional coating application methods such as, for example, brushing,rolling, drawdown, dipping, curtain coating, and spraying methods suchas, for example, air-atomized spray, air assisted spray, airless spray,high volume low pressure spray, and air-assisted airless spray may beused in the method of this invention. Wet coating thickness of theapplied aqueous coating composition may range from 5 μm to 150 μm. Theaqueous coating composition may be applied onto a substrate as a singlecoat or multiple coats. Preferably a single coat of the aqueous coatingcomposition is applied. The applied aqueous coating composition may bedried by the application of heat or, alternatively, the applied aqueouscoating composition may be allowed to dry. Convective, conductive, andradiative heating methods may be used to dry the wet coating of theaqueous coating composition. Suitable temperatures for drying theapplied aqueous coating composition are 10° C. to 120° C. The substrateincluding the dried coating of the aqueous coating composition, referredto as the “precrosslinked coated substrate”, may be cured by heating theprecrosslinked coated substrate to provide the coated substrate of thisinvention. Temperatures suitable for crosslinking include temperaturesin the range of 20° C. to 300° C. The heating time for crosslinking mayvary with the type of crosslinking agent, the thickness of the coating,and the crosslinking temperature. Typical heating times for crosslinkingmay range from less than 1 minute to greater than 1 hour. Alternatively,the applied aqueous coating composition may be dried and crosslinkedsimultaneously.

In one embodiment, the aqueous coating composition is applied onto anelastomeric substrate including EPDM rubber, dried, and crosslinked. Thecoated elastomeric substrate is useful as weatherstrip on vehicles suchas cars and trucks. Other uses for the coated elastomeric substrateinclude household weatherstrip, industrial weatherstrip, windshieldwiper blades, and gaskets for various articles such as luggage.

EXAMPLE 1

Preparation of Aqueous Coating Composition

The aqueous coating composition of this invention was prepared by mixingthe materials listed in Table 1.1 while maintaining a pH above 6.5 withthe addition of ammonia. The aqueous coating composition had a solidslevel of 42 % and a pH of 8.0. TABLE 1.1 Composition of Aqueous CoatingComposition Component Amount Material and Supplier polyurethane polymer61.13 g Neorez ™ R9409 resin (Neoresins) (32 wt. % solids) deionizedwater 5.54 g flatting agent 6.00 g Lo-Vel ™ 2023 silica (PPG) slip aid2.32 g Microspersion HT wax dispersion (Micro Powders, Inc.) (50 wt. %solids) slip aid 1.93 g Aqua Polysilk 19 wax (Micro Powders, Inc.) UVstabilizing agent 2.32 g Raven Water Black pigment (Columbian Chemicals)crosslinking agent 16.10 g Epocros ™ K-2010E polymer (Nippon ShokubaiCo, Inc.) slip aid 3.85 g Teg Protect ™ 5000 silicone resin (TEGOChemie) wetting agent 0.81 g Byk 333 ™ wetting agent (BYK Chemie)

EXAMPLE 2

Application and Testing of the Aqueous Coating Composition

The aqueous coating composition of Example 1 was applied to an untreated15 cm×15 cm molded EPDM rubber substrate by drawdown with a wire woundrod. The wet coating thickness was 75 μm. The samples were dried andcured at 245° C. for 2 minutes to provide the coated substrate of thisinvention.

The properties of the coated substrate were evaluated according to thefollowing test procedures.

The durability of the coated substrate was evaluated according thetoluene double rub test, SP TP 88 (Standard Products). The coatedsubstrate was tested 24 hours after curing. Acceptable durability was avalue of 200 or greater cycles.

The cold flexibility of coated substrate was evaluated according to theFord WSB-M2D49A2 test. The coated substrate was exposed to a temperatureof −40° C. for a period of 16 hours. Acceptable cold flexibilityproperties were the absence of cracks or the loss of adhesion.

The test procedure for determining the coefficient of friction was ASTMD 1894.

The coated substrate prepared from the aqueous coating composition ofExample 1 had the following test results: Durability Test 200 cyclesCold Flexibility Test pass Coefficient of Friction Test 0.3

The test results show that the aqueous coating composition of thisinvention provides a substrate with durability, acceptable flexibilityat low temperature, and a low friction surface, as characterized by acoefficient of friction of less than 3. The aqueous coating compositionhad good adhesion to untreated EPDM rubber, a low energy surface.

1. An aqueous coating composition comprising, based on the weight ofsaid aqueous coating composition: a) from 10 to 70 weight % of at leastone polyurethane polymer, wherein said polyurethane polymer contains atleast two carboxylic acid groups; b) from 1 to 60 weight % of at leastone crosslinking agent; c) from 0.01 to 4 weight % of at least onewetting agent; d) from 0.1 to 15 weight % of at least one slip aid; ande) from 0.01 to 20 weight % UV stabilizing agent.
 2. The aqueous coatingcomposition according to claim 1 wherein said polyurethane polymer hasan acid number in the range of 5 to
 50. 3. The aqueous coatingcomposition according to claim 1 further comprising from 0.5 to 20weight % flatting agent.
 4. The aqueous coating composition according toclaim 1 wherein said crosslinking agent contains oxazoline groups.
 5. Amethod of preparing a coated substrate comprising the steps of: a)preparing an aqueous coating composition comprising: i) from 10 to 70weight % of at least one polyurethane polymer, wherein said polyurethanepolymer contains at least two carboxylic acid groups; ii) from 1 to 60weight % of at least one crosslinking agent; iii) from 0.01 to 4 weight% of at least one wetting agent; iv) from 0.1 to 15 weight % of at leastone slip aid; and v) from 0.01 to 20 weight % UV stabilizing agent; b)applying said aqueous coating composition to a substrate; c) drying orallowing to dry said aqueous coating composition to provide aprecrosslinked coated substrate; and d) curing or allowing to cure saidprecrosslinked coated substrate to provide said coated substrate. 6) Themethod of claim 5 wherein said substrate is selected from the groupconsisting of chlorosulfonated polyethylene rubber, ethylene-propylenerubber, ethylene-propylene-diene rubber, halogenated nitrile rubber,thermoplastic elastomers, thermoplastic polyolefins, propylene oxidepolymers, and epichlorohydrin polymers. 7) The method of claim 5 whereinsaid coated substrate has a coefficient of friction of 3 or less. 8) Anarticle comprising a coated substrate comprising: a) a substrate; and b)a coating prepared from an aqueous coating composition comprising: i)from 10 to 70 weight % of at least one polyurethane polymer, whereinsaid polyurethane polymer contains at least two carboxylic acid groups;ii) from 1 to 60 weight % of at least one crosslinking agent; iii) from0.01 to 4 weight % of at least one wetting agent; iv) from 0.1 to 15weight % of at least one slip aid; and v) from 0.0.1 to 20 weight % UVstabilizing agent. 9) The article according to claim 8 wherein saidsubstrate is selected from the group consisting of chlorosulfonatedpolyethylene rubber, ethylene-propylene rubber, ethylene-propylene-dienerubber, halogenated nitrile rubber, thermoplastic elastomers,thermoplastic polyolefins, propylene oxide polymers, and epichlorohydrinpolymers. 10) The article according to claim 8 wherein said coatedsubstrate has a coefficient of friction of 3 or less.